FIG. 2.

Mutation of the S516 and S645 phosphorylation sites in Artemis causes a prolonged G₂/M delay after IR. (A) Immunoblot showing kinetics of phosphorylation and dephosphorylation of GST-Artemis at the indicated sites after exposure to IR. (B) Immunoblot showing expression of the indicated Artemis wild-type and mutant proteins in HEK293 cells. (C) Cell cycle analysis after IR of HEK293 cells stably expressing wild-type Artemis or the S516/645A or S516/645D mutant. (D) Graphical analysis of results shown in panel C. (E) Phospho-histone H3 (P-H3) staining analysis of wild-type and mutant Artemis cell lines after exposure to IR. (F) Cell cycle analysis of Artemis-expressing cells pulse-labeled with BrdU and immediately exposed to IR. WT, wild type; GAPDH, glyceraldehyde-3-phosphate dehydrogenase.